Hoist jack



Jan. 8, 1952 F. w. COFFING 2,581,577

HOIST JACK Filed Feb. 18, 1950 2 SHEETS--SHEET 1 INVENTOR.

[KfDK/C'A 14f Farr/Na 1952 F. w. COFFING 2,581,577

HOIST JACK Filed Feb. 18, 1950 2 SHEETS--SHEET 2 INVENTOR. 2750mm #4(bf/Wm Patented Jan. 8, 1?52 HOIST JACK Fredrick W. Coiling, Danville,111., assignor to Coffing Hoist Company, Danville, 111., a corporationApplication February 18, 1950, Serial No. 145,075

6 Claims. 1

This invention relates to a hoist structure that comprises a pair ofpawls, an oscillatory handle, a housing and a wheel therein arranged tosupport a flexible, relatively inextensible elongated means such as alog or coil chain, a sprocket or side link and pintle chain, or a web ortape.

In each instance the wheel conforms to the said means, thus a pocketwheel can be utilized with the log chain, a sprocket wheel with thesprocket chain, and a corrugated wheel with the tape or web. In thefirst instance the fiatwise links on the wheel provide pawl abutments,in the second instance the sprocket chain pintles and the like providepawl abutments, and in the last instance the wheel corrugations conformthe tape to provide abutments therein for pawl association.

In each of the aforesaid types the operative ends of the pawls areidentical, and each pair conforms to the flexible means, all as morefully illustrated in the copending application Serial No. 148,727, filedMarch 9, 1950, and entitled Full Automatic Hoist and Binder.

The foregoing is set forth to emphasize the universal adaptability ofthe present invention for herein the sprocket chain embodiment only hasbeen selected for purposes of illustration. It is further pointed outthat while this selected form bears some resemblance to the hoist shownin Patent No. 2,377,324, dated June 5, 1945, and the present hoist has,in common therewith, the parts initially enumerated herein and the basicmovements of the said similar parts are similar,

the present invention is otherwise essentially different as hereinafterpointed out.

Herein merely to emphasize departures from said patented hoist, theinvention is illustrated in the form wherein the pawls engage thesprocket teeth on the wheel, although the wheel need not include suchteeth, see said application aforesaid.

The chief object of the present invention, is to provide a hoist of thetwo pawl, oscillatory handle type wherein load moving in oppositedirections, as for example load raising and load lowering, is effectedin step by step increments and automatically in that no separate oradditional manual control is required to shift from one operation ormovement to the other.

The chief feature of the present invention resides in oscillation of thehandle to difierent degrees of the total possible handle oscillation tothereby selectively effect load raising and load lowering, these termsbeing utilized herein in their bread relative sense as previouslyindicated.

In the present invention so-called free chain movement can be effected.In this instance a. manually operable control is provided. This featureis broadly disclosed in the aforesaid patent but herein, asdistinguished therefrom, the handle, when the hoist is manuallyconditioned for free chaining, is locked against oscillation.

The present invention has the further advantage that for successfuloperation it is not dependent upon critical values of the springsassociated with the pawls, which dependency is present in the aforesaidpatented hoist. The present invention, accordingly, eliminates inproduction, dependence upon spring manufacturers, in other words, thepresent hoist is positive and certain in operation regardless of minorvariations in springs.

Other objects and features of the invention will be set forth more fullyhereinafter.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims.

In the drawings, Fig. 1 is a side elevation of a sprocket embodiment ofthe invention, one side plate of the housing being omitted, the partsbeing shown in the up limit of handle movement for load raising.

Fig. 2 is a similar view, the parts being shown in the down limit ofhandle movement for load raising.

Figs. 3 and 4 are similar views respectively for load lowering.

Fig. 5 is a similar view with parts in the free chain position.

Since the hoist selected for illustration is of the sprocket chain type,and since the invention can work directly upon the flexible means or thesprocket wheel, if such a wheel be used, the illustration of the chainis omitted for clearness and the dual pawls have notched ends forsprocket tooth engagement as shown in said patent.

In the several views, 10 indicates a plate-like half housing with whichis associated, as shown in said patent, a complementary half-housing H,see Figs. 3 and 5. An anchoring hook I! is swiveled at 13 therein. Thishousing has chain intake [4, chain outlet I5 and an intermediate divideror partition l6 which is relieved at I! for tooth clearance when asprocket type wheel I8 is utilized as shown herein. The housing,opposite the intake I4, includes the handle accommodating slot 19.

Wheel I8 includes teeth l8 and is mounted on shaft 20. .A. bifurcatedhandle forming member having spaced arms 2| is also mounted on said 2|and rides in said notch 34. plates 3| and pins 31 may be utilized.

shaft 20 and terminates in a socket 22 that detachably receives a handleextension that may comprise a pipe 23 threaded into the socket ifdesired or may be otherwise detachably secured thereto.

Load holding pawl 24 is pivoted in the housing upon shaft 25 or may berigid therewith whereupon said shaft 25 then is pivoted in the housing.

The holding pawl in this embodiment has notched end 24 for reasonsassigned in said patent. A spring 26 is anchored to pawl 24 at one endby pin 38 and to the housing at the opposite end 26 It normally tends toconstrain the holding pawl 24 into sprocket or flexible meansengagementdepending upon the particular wheel and means utilized.

lhe load moving pawl 21 herein has notched ing cam plate 3|, see Figs.3, 4 and 5. It includes a tongue portion 32 having cam Surface 33.

It also includes concentric arouate notch 34 with upper andflower endwalls 35 and 38 respectively. Herein the cam plate is disposed betweenthe handle arms 2| so herein cam plate actuating pin 3! extends inwardlyfrom the adjacent arm If desired dual For load raising the handle andpawl operation is as disclosed in said patent except that herein pin 3!rides freely in the notch 34 aforesaid and does not effect any movementof said cam plate or plates. For load lowering the handle is broughtdownfa'rther, compare Figs. 2 and 4, and in this movement pawl 21 iswheel or means engaged and the pin 31 engages end wall 36 to tilt thecam 3| clockwise to have the face 33 of tongue 32 engage the holdingpawl 24 at pin 38, see Fig. 4. Slight further downward movement of thehandle removes the draft lock on pawl 24 and then the holding pawl 24 iscam tilted by face 33 'means, see Fig. 3. Further upward movement of thehandle now effects moving pawl 21 tilting to the non-engaging positionwhich will be described.

4 to oscillation of holding pawl cam 24, the moving pawl cam 39 is movedby the housing abutments (pins) 4| and 42. As the handle is brought downto take a new bite on the chain, cam 39 engages stop 42 which tilts thecam counter-clockwise from the position shown in Fig. 3.

Thereupon the cam 39, is relieved from plate 44 and holding pawl 27 issnapped by spring 29 into engagement with the sprocket. The load is nowheld by pawl 21. When this is effected further handle movement relievesthe draft on holding pawl 24 and cam tongue 32 is tilted to tilt thepawl 24 to the position shown in Fig. 4.

r Then with one pawl in and the other out the handle is raised from theposition shown in Fig. 4 to that shown in Fig. 3. Near the end of thishandle movement the cam tongue 32'is retracted from the holding pawl 24and it returns toward holding position and takes the load just beforecam 39 engages pin 4| to force pawl 21 from the chain and lock out thispawl, see'Fig. 3; When this is efiected the handle is lowered to theposition shown in Fig. 4 for the moving pawl to take another bite. Theaforesaid describes load lowering.

For free chaining, with no load upon the chain, the handle is. broughtdown, see Fig. 4, to lock up the load holding pawl 24. Then the handleis brought up to the position shown in Fig. 5. The

housing includes a pair of spaced stops 45 and 46.

Pivoted'on the handle at 41 between it and the housing is a cam 48having manually actuable Having thus described holding pawl control inload lowering operation reference will now be had to moving pawlcontrol. This also is cam effected and the control cam is tiltablymounted. Herein cam 39 is pivoted at 40, see Fig. 3, upon one arm 2| ofthe handle and disposed between that arm and the adjacent housing.

tail or finger piece 49. When this cam is tilted, see Fig. 4, clockwise,see Fig. 5, it engages plate 44 opposite from the cam 39 engaged portionthereof and tilts the moving pawl 21 counterclockwise against its spring29. This, if there be no load upon the chain, then frees the chain fromthe moving pawl.

While. the chain can be. freely moved in either direction it is highlydesirable to prevent handle oscillation and prevent other undesirableoperations and to permit the operator to let goof cam 48. Accordingly,cam 48 mounts a pin 50.

The efiect thereof is such that cam 48 cannot 'be tilted clockwise toeffect free chaining until the handle 22 is properly disposed for thepin 50 to enter between the aforesaid abutments 4546. When sov entered,see Fig. 5, the cam 48 is tilted clockwise, the load moving pawl 21 islocked out and. the handle 22 cannot oscillate. To release the hoist foroperation tail 49 is tilted counterclockwise. Cam 48 disengages fromplate 44 and spring 29 snaps pawl 21 into sprocket engagement, theholding pawl 24 being still held out, see. Fig. 4. Then the handle canbe short range oscillated for load elevation or long range oscillatedfor load lowering as desired or required.

Except for free chaining, and if desired handle looking, no additionalmanually operable memher is required for load lowering or raising or forshifting from one to the other.

While the invention has been illustrated and described in great detailin the drawings and foregoing description, the same is to be consideredas illustrative and not restrictive in charac er.

Theseveral modifications described herein as well as others which willreadily suggest themselves to persons skilledv in this art, all areconsidered to be within the broad scope of the invention, referencebeing had to the appended claims. r

The invention claimed is:

1. In a hoist for moving a flexible inextensible means therethrough andhaving a reversibly rotatable wheel for means support, a handleoscillating about the axis of wheel rotation, a load holding pawlpivotally supported adjacent said wheel and normally constrained towardwheel or means engagement, and a load moving pawl pivotally supportedupon the handle and normally constrained toward wheel or meansengagement, the combination therewith of a floating cam oscillatory uponthe wheel axis, said cam having arcuately spaced abutments, a handlecarried means disposed in juxtaposition to said abutments andselectively engageable therewith in handle oscillation, a followercarried by the holding pawl and selectively engageable with said cam anddisengageable therefrom in cam oscillation incident to handle operation,a second cam carried by said handle for moving said moving pawl out ofoperative position and means stationarily mounted relatively to saidhandle and rendered effective for controlling the operation of saidsecond cam moving means by the oscillation of said handle.

2. In a hoist having an oscillatory handle, a pair of pawls, a housing,an inextensible flexible means, a wheel for the latter, and in thehousing. and a spring for each pawl, one pawl being carried by thehousing and the other by the handle, the combination of a pair of spacedabutment means, a manually tiltable means, one of said last twomentioned means being carried by the housing and the other being carriedby the handle, a lock carried by the tiltable means and movable into thespace between the spaced abutment means for handle locking, a pair ofoscillatory cams, one for each pawl for effecting pawl throwout and holdout thereof, and an actuator means for each cam operable in the relativemovement of the handle.

3. In a hoist having an oscillatory handle, a pair of pawls, a housing,an inextensible flexible means, a wheel for the latter, and in thehousing, and a spring for each pawl, one pawl being carried by thehousing and the other by the handle, the combination of a pair of spacedabutments, a manually tiltab le means, one of said last two mentionedmeans being carried by the housing and the other being carried by thehandle, a

lock carried by the tiltable means and movable into the space betweensaid abutment means for handle locking, a pair of oscillatory cams, onefor each pawl, for effecting pawl throwout and holdout thereof, and anactuator means for each cam operatively effective thereon in therelative movement of the handle, one actuator means being carried by thehandle and the other by the housing.

4. In a hoist having an oscillatory handle, a pair of pawls, a housinghaving an inextensible flexible means, a wheel for the latter and in thehousing, and a spring for each pawl, one pawl being carried by thehousing, and the other by the handle, the combination of a pair ofspaced abutment means, a manually tiltable means, one of said last twomentioned means being carried by the housing, and the other beingcarried by the handle, a loclr carried by the tiltable means and movableinto the space between the spaced means for handle looking, a pair ofoscillatory cams, one for each pawl, for effecting pawl throwout andholdout thereof, and an actuator means for each cam operativelyeffective thereon in the relative movement of the handle, one actuatormeans comprising a pin carried by the handle and the other actuatormeans being carried by the housing.

5. In a hoist having an oscillatory handle, a pair of pawls, a housing,an inextensible flexible .means, a wheel for the latter, and in thehousing, and a spring for each pawl, one pawl being carried by thehousing and the other by the handle, the combination of a pair of spacedabutment means, a manually tiltable means, one of said last twomentioned means being carried by the housing and the other carried bythe handle, and a lock carried by the tiltable means, and movable intoand against said spaced abutment means for handle looking, a pair ofoscillatory cams, one for each pawl, for effecting pawl throwout andholdout thereof, and an actuator means for each cam operativelyeffective thereon in the relative movement of the handle, one actuatormeans being carried by the handle and the other by the housing, one ofsaid actuator means comprising a pair of spaced carried abutments.

6. In a hoist for moving a flexible inextensible means therethrough andhaving a reversibly rotatable wheel for means support, a handleoscillating about the axis of wheel rotation, a load holding pawlpivotally supported adjacent said wheel and normally constrained towardsaid wheel for means engagement, a load moving pawl pivotally supportedupon the handle and normally constrained toward said wheel for meansengagement, the combination therewith of a floating cam oscillatory uponthe wheel axis, said cam having arcuately spaced abutments, a handlecarried means disposed in juxtaposition to said abutments andselectively engageable therewith in handle oscillation, a followercarried by said holding pawl and selectively engageable with said camand disengageable therefrom in cam oscillation incident to handleoperation, an oscillating load pawl control cam carried by said handle,operatin means for said load pawl and spaced stop means engageable withsaid load pawl control cam for moving said cam into and out ofengagement with said load pawl operating means.

FREDRICK W. COFFING.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS

